Problem: Multiply, reduce to lowest terms, and write as a mixed number: $ 5\dfrac{1}{4} \times 3\dfrac{3}{4} $
Solution: $ = \dfrac{21}{4} \times \dfrac{15}{4}$ $ = \dfrac{21 \times 15}{4 \times 4}$ $ = \dfrac{315}{16}$ $ = 19 \dfrac{11}{16}$